Good Village Idiots are hard to find. It's a specialist skill that goes back generations, passed from unknown father to son.
However, other skills are passed from teacher to student over the generations. And in particular, making frets shiny is a highly valued skill.
After levelling, shaping the fret ends, and re-profiling you need to keep the masking tape in place. Then you need to remove the coarse fret file marks with wet & dry paper. I like to soak mine in white spirit for a few minutes first, it helps make the backing paper pliable so it easily matches the profile of the frets.
After that, I like to use fine wire wool to polish them to the next stage. You can easily buy 0000 wire wool, and you can do an acceptable job with that, but my secret weapon is a stash of 000000 wire wool. It's not easy to find, but worth the effort. You don't need a lot, my original supply lasted me a good decade and when it was close to running out I was chatting to a fisherman who used to make his own flies and had a big bundle that he didn't use any more. That's already lasted me a few years and there's at least another 10 years worth left. You don't need a lot. You need to find some of the more specialist woodwork suppliers online to get it, but it really is worth it.
And then to make things as smooth as possible, it's time to break out the Brasso and elbow grease. Apply with gusto, rubbing along the length of the fret. And once all are highly polished, buff of the excess. Remove the masking tape, and buff again with a soft, clean, cloth and you too can have shiny frets like these.
Day off tomorrow. Fine sandpaper time starts on Monday.
When the going gets weird, the Weird turn Pro.